In a small saucepan, bring 2 cups of water to a boil. Once boiling, remove from heat and add the dried lavender. Let steep for about 15 minutes.
Strain the lavender-infused water through a fine mesh sieve into a bowl, discarding the lavender flowers.
In a large pitcher, combine the lavender water, fresh lemon juice, and granulated sugar. Stir until the sugar is fully dissolved.
Add the coconut water and 4 cups of cold water or sparkling water to the pitcher. Stir gently to combine.
Chill the lemonade in the refrigerator for at least 30 minutes before serving.
Serve over ice and garnish with fresh lemon slices and lavender sprigs.